Apparatus for indicating torque applied to pipe rotated by a rotary table

ABSTRACT

Apparatus for indicating the torque applied to a rotated member, particularly pipe rotated by a rotary table in the drilling of a well, wherein the apparatus is connected to the drive shaft of the rotary table, and power to the rotary table is supplied through the apparatus.

United States Patent Bell [4 1 June 13, 1972 [72] Inventor: Leo A. Bell,Villa Maud, Kappara Road,

San Gwann, Malta [221 Filed: Sept. 9, 1970 21 App1.No.: 70,660

[52] 11.8. CI. ..73/136 R, 73/140 [5|] ..G0ll 3/14 [58] Fleld Search..73/136 R, 140

[56] References Cited UNITED STATES PATENTS 2,593,000 4/1952 Bayless..73/136 D 2,582,784 111952 Lumb et al. ...73/l36 R 2,718,782 9/1955Steinbruegge et al ..73/136 R 1,789,862 l/193l Bricken ..73/136BX2,061,896 11/1936 Chilton 3,176,510 4/1965 Kimmell et a1 ..73/144FOREIGN PATENTS OR APPLICATIONS 376,054 5/1907 France ..73/136 R 6,3617/1908 Great Britain .....73/1 36 R 1,919,398 10/1969 Germany ..73/136 DPrimary ExaminerCharles A. Ruehl Anarney-Pravel, Wilson & Matthews 1 1ABSTRACT Apparatus for indicating the torque applied to a rotatedmember, particularly pipe rotated by a rotary table in the drilling of awell, wherein the apparatus is connected to the drive shaft of therotary table, and power to the rotary table is supplied through theapparatus.

9 Claims, 7 Drawing Figures PATENTEDJUH131972 I 3,688,926

SHEET 2 BF 2 INVENTOR.

' Pat. No. 2,741,118

- l APPARATUS OR INDICATING TORQUE APPLIED TO PIPE RO'IATED BY A ROTARYTABLE BACKGROUND OF THE INVENTION The field of this invention isapparatus for indicating torque applied to a pipe, shaft, or othermember.

In the past, torque which has been applied to gear systems as in US.Pat. Nos. 2,386,367; and 2,899,822; and to ball screw and nut assembliesas in US. Pat. No. 3,230,762 has been indicated. Torque analyzers suchas disclosed in U.S.

are also known. Various types of measuring and indicating devices havebeen used in connection with drilling rigs, an example of which is shownin US. Pat. No. 3,382,713. However, despite such general informationwith respect to torque, and the specific other measurementapplications'in connection with drilling rigs, so far as is known, noone has ever heretofore invented an apparatus for indicating the torqueapplied to drill pipe by the rotary table.

SUMMARY or THE INVENTION The present invention relates to an apparatusfor indicating the torque applied to pipe rotated by a .rotary table forthe drilling of a well or for similar operations. By such indication ofthe torque applied to pipe, the driller or operator may detect changesin the formations encountered by the drill bit, and he will be able toavoid the application of excessive torque to the pipe which mightpermanently twist or deform the pipe, oreven shear it, thereby avoidingdangerous conditions of the pipe which might not otherwise be known tothe driller or operator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the apparatusof this invention, including a conventional rotary table in combinationwith the apparatus for indicating torque applied to pipe rotated by therotary table;

' FIG. 2 is a sectional view taken on line 22 of FIG. 1 to illustrate inparticular one form of the apparatus of this invention;

FIG. '3 is a view taken on line 3-3 of FIG. 2 to illustrate furtherdetails of the first form of this invention;

F IG. 4 is a sectional view taken on line 4-4 of FIG. 5, illustratinganother form of the invention;

FIG. 5 is 'a partial sectional view corresponding to FIG. 2, butillustrating another embodiment of the present invention; FIG. 6 is asectional view taken on line 6-6 of FIG. 7; and

FIG. 7 is a partial sectional view, corresponding to FIG. 5,

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter Adesignates generally the apparatus of this invention which is adapted tobe connected to a drive shaft10 of a rotary table R of conventionalconstruction. The rotary table R is adapted to rotate drill pipe P forthe drilling of a well in the usual manner. Briefly, the apparatus A,is'adapted to be driven by a conventional chain from a drawworks (notshown) so as to transmit through the apparatus A the power to drive therotary table R and thus to rotate the pipe P. The apparatus A is soconstructed that an indication of the torque applied to the drill pipe Pby the rotary table R is indicated. v i

The apparatus A includes a hub 12 which has a central bore 12a forreceiving the rotary table drive shaft 10. The hub 12 is secured to thedrive shaft 10 by a locking key 14 which is positioned in a keyway 10ain the drive shaft 10 and a similar keyway 12b in the hub 12. The key 14is preferably forced into the keyways 10a and 12b so as to prevent bothrotational movement and longitudinal movement of the hub 12 relative tothe shaft 10.

In the form of the invention illustrated in FIGS. 2 and 3, the hub 12 isprovided with a central splined section having but showing a stillfurther embodiment of the present invenspaced inclined splines 12ctherewith. As will be explained, the splines 120 project externally fromthe hub 12 and are spaced circumferentially with respect to each otherso as to form inclined grooves or recesses 12d therebetween. The splines12c are inclined with respect to the-longitudinal axis of the centralbore 12a of the hub 12 and the central longitudinal axis of the driveshaft 10.

An outer sprocket sleeve 20 having sprocket teeth 20a so as to receive aconventional chain from a drawworks, surrounds the hub 12. The sprocketsleeve 20 has a plurality of inwardly extending splines 20b which fitinto, and partially fill the grooves 12d in the hub 12 (FIG. 2). Thesplines 20b are inclined at the same, or substantially the same, angleas the splines 12c, but are spaced therefrom and receive therebetweenantifn'ction thrust bearings 22 which are formed on any suitableantifriction material such as phosphor-bronze.

It is to be noted that the width'of the sprocket sleeve 20 is slightlygreater than the width of the splines 20b and 12c and the width of thebearings 22. It should also be pointed out that the hub 12 hascylindrical end surfaces l2e and 12f which are of a reduced diametercompared to the diameter in which the external surfaces of the splines12c lie, thereby forming annular ends 12g and 12h at the outerextremities of the hub 12.

A retainer ring 25 is secured to the end of the sprocket sleeve 20 whichis closest to the rotary table R and it serves to limit the movement ofthe sprocket sleeve 20 in a direction to the left as viewed in FIG. 3,due to the engagement of the retainer ring 25 with the end 12g of thehub 12. A suitable seal such as an O-ring 25a is disposed in theretainer ring 25 for engagement with the external cylindrical surface12a of the hub 12 to retain grease within the area of the splines 12cand 20b.

At the left end of the sleeve 20, a similar retainer ring 26 is securedto the sleeve 20 to limit the extent of movement of the sprocket sleeve20 in the right hand direction (as viewed in FIG. 3) by the engagementthereof with the end 12h of the hub 12. A seal such as an O-ring 26a ismounted with the retainer ring 26 for also confining lubricant such asgrease within the area of the splines 12c and 20b. The retainer rings 25and 26 are secured to the sleeve 20 by any suitable means such as screwsor bolts 25b and 26b, respectively.

An indicator means or unit 30, which may be of known construction,includes a housing 31 having a flexible diaphragm 32 supported thereinso as to divide the housing into chambers 31a and 31b. The diaphragm 32has a portion thereof of inherent flexibility such as rubber to which isconnected a piston or projecting element 33 which moves with thediaphragm 32. The element or piston 33 extends through an opening 310 inthe housing 31. A passage 33a is formed in the piston 33 forestablishing communication from the chamber 31a to the chamber 31b, andthen to the atmosphere through an outlet port 31d. The passage 33a isclosed by a valve element 34 which is connected by a rod 35 to anothervalve 36. The valve 36 is adapted to close a passage 3le which is in thechamber 31a for supplying air to such chamber 31a when the valve 36 isunseated with respect to the opening 3le.

Air is supplied to the chamber 31a through the port 3le when the valve36 is unseated, preferably through a swivel inlet or chamber 40 which isswivel-mounted so as to remain stationary when the housing 30 isrotated. The swivel mounting is accomplished by any suitable means, suchas a retainer ring 41 which is secured to the housing 30 by bolts orscrews 41a or other suitable meanspAn O-ring 41b or other sealing meansis provided to prevent the loss of air during the relative rotation ofthe housing 30 with respect to the swivel inlet or chamber 40. Theswivel inlet or chamber 40 has an air supply line 42 connected therewithand with a suitable source (not shown) of air under pressure. A signalline 43 extends from the chamber 31a and is connected by a flexible line(not shown) to a gauge 45 which is located at any suitable point,generally remote from the apparatus A, at the drillers instrumentconsole (not shown). The gauge 45 has a pointer 45a and is calibrated soas to show readings in pounds per square inch of air pressure, or it maybe calibrated to read in foot pounds of torque which is applied to thedrill pipe P. In either event, the pointer 45a will indicate therelative amount of torque being applied to the drill pipe P by therotary table R. It will be appreciated that other types of gauges orindicators, including marking pen or stylus types, may be utilized for apermanent and continuous record if so desired.

The housing 30 is attached to the retainer ring 26 by means of bolts 37,or any other suitable securing means so that the housing 30 moves withthe sprocket sleeve 20 in a longitudinal direction relative to thelongitudinal axis of the drive shaft 10. Also, the housing 30 rotateswith the sprocket sleeve 20, but the swivel inlet 40 and the supply line42 and the signal line 43 remain stationary.

In the operation or use of the apparatus A of this invention, it issecured to the outer end of the drive shaft of a conventional rotarytable R, with the piston 33 in engagement with the end 10a of the driveshaft 10 (FIG. 3). The piston 33 continues to remain in constantengagement with the end 10a of the drive shaft 10 during the movementsof the rest of the apparatus, as will be more evident hereinafter.

The sprocket teeth a are engaged with the drawworks chain so that thesprocket sleeve 20 is driven by the drawworks, and the rotation thereofis transmitted through the splines 20b and the bearing 22 to the splines12c of the hub 12 to thereby impart rotation to the drive shaft 10 whichis connected to the hub 12.

Additionally, depending upon the resistance developed due to the torqueon the pipe P during the rotation thereof with the rotary table R, thesprocket sleeve 20 tends to move in a longitudinal direction (eitherright or left in FIG. 3), but the extent of the longitudinal movement islimited because of the inclination of the coacting splines 20b, 12c andthe bearing members 22 therebetween. Thus, as the torque on the drillpipe P increases, there is a tendency for the sprocket 20 to movefurther to theright as viewed in FIG. 3, whereas, as the torque on thedrill pipe P decreases, there is a tendency for the sleeve 20 to move tothe left as viewed in FIG. 3. The extent of such movement in eitherdirection is not great, but it is sufficient to affect the situationwith respect to the indicator apparatus or unit 30.

For example, when the sprocket 20 moves to the right, it moves relativeto the hub 12 and it moves the housing 30 therewith. The piston orprojection 33, on the other hand, cannot move to the right with thehousing 30 because it is engagement with the shaft 10 which does notmove to the right. Thus, when the housing 30 moves to the right from theposition shown in FIG. 3, the valve 36 is unseated because the housing30 in effect moves away from the valve 36 to open the port 31a to permitair pressure from the supply line 42 to enter the chamber 31a. The valve34 remains seated so that the passage 33a is closed while air is beingadmitted into the chamber 31a so that the pressure within the chamber31a increases and acts to force the housing 30 back to the left,carrying with it the sprocket 20, until the valve element 36 has againseated to close the passage 1312. Upon a reseating of the valve 36, thepressure within the swivel inlet or chamber 40 has increased to the sameextent as the pressure within the chamber 31a and this is indicatedthrough the signal tube 43 at the gauge 45 so that the operator canvisually see that there has been an increase in the torque on the drillpipe P.

When the torque on the drill pipe P decreases, the housing 30 and thesprocket sleeve 20 are moved to the left as viewed in FIG. 3 by thepressure in the chamber 31a. Since the valve element 36 is movable tothe left with the housing 30 and it is connected through the stem 35 tothe valve element 34, such movement of the housing 30 to the left causesan unseating of the valve element 34 to open the passage 33a whichdischarges some of the air pressure in the chamber 31a through thepassage 33a and outwardly to atmosphere through the port 31d. When thepressure in the chamber 31a drops sufficiently, the housing 30 moves tothe right again and ultimately the valve element 34 is seated so thatfurther movement of the housing 30 at that time is prevented. It is tobe noted that the air pressure in the chamber 40 is at all times greaterthan the signal pressure in the chamber 31a.

Thus, the gauge 45 or other suitable indicator connected to the chamber31a continuously indicates the air pressure changes within the chamber31a, which changes are proportional to the changes in the torque appliedto the drill pipe P. It should also be noted that when the pressuredropped in the chamber 31a, the housing 30 and the sleeve 20 moved backto the right to a substantially center position again. Thus, the sleeve20 may move back and forth relatively short distances with respect tothe hub 12 and the shaft 10 in a longitudinal direction as the torque onthe drill pipe P varies. A constant indication of the torque on thedrill pipe P is thus obtained at the gauge 45 or other suitableindicator means.

In FIGS. 4 and 5, a modified apparatus A-l is illustrated, wherein likeparts as compared to FIGS. 1-3 bear like numerals and/or letters. Thus,the hub 12 in FIGS. 4 and 5 is the same as hub 12 of FIGS. 2 and 3, andthe sprocket sleeve 20 is the same in both forms of the invention.However, the forcetransmitting means is modified in that splines 112aand 120k are different from the corresponding splines 12c and 20b. The

splines 1 120 and 12% are not inclined with respect to the longitudinalaxis of the shaft 10. Also, in FIGS. 4 and 5, the bearing members 22have been omitted, and in place thereof, special bearings 122 have beensubstituted. Each of the bearings 122 is provided with a pair of bearingraces 122a and 122k which are formed with inclined grooves for receivinga plurality of roller or ball bearings 1226. Such construction providesthe same effect as the inclined splines 12c and 20b illustrated in FIGS.2 and 3 since torque forces applied to the sprocket sleeve 20 of FIGS. 4and 5 causes a longitudinal relative movement of the sleeve 20 withrespect to the fixed hub 12 in the same manner as heretofore describedin connection with FIGS. 2 and 3.

In FIGS. 6 and 7, another modified fonn of the invention is illustrated,wherein parts which are similar to those of FIGS. 2 and 3 bear likenumerals and/or letters. The force-transmitting means is again modifiedby providing the sleeve 20 and the hub 12 with straight splines or ribs2120 and 220b instead of the inclined splines 12c and 20b of FIGS. 2 and3. The ribs 220b and 2120 are spaced apart from each other and areinterconnected by pivoted links which are pivotally connected at pivotpins 800 and 80b. The links 80 fit within suitable inclined slots 220Cand 212d in the ribs 220b and 2120, respectively. The links 80 aredisposed at an angle to a radial plane passing through the sleeve 20 sothat as torque is applied to the drill pipe P, there is a tendency forthe links 80 to move to a straight position in the radial plane passingthrough the shaft 10, and such movement causes a longitudinal shiftingof the sleeve 20 in FIGS. 6 and 7 in the same manner as the longitudinalshifting of the sleeve 20 in FIGS. 2 and 3. Thus, the operation of thesleeve 20 and the indications at the gauge 45 are the same in themodified forms of the invention illustrated in FIGS. 4-7 as thatexplained heretofore in connection with FIGS. 2 and 3.

It should be understood that the various force-transmitting means whichare disclosed in the various embodiments in the drawings provide forinterconnecting the sleeve 20 with the hub 12, and such illustratedmeans are merely exemplary, since other forms thereof may be providedfor accomplishing the same result heretofore described in connectionwith FIGS. 2 and 3.

It should be emphasized that, although the invention has beenspecifically described for indicating torque variations in drill pipe,the invention has a much broader field of use, since it can be used forindicating torque applied to driven shafts and other rotated members invarious systems and arrangements.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

1 claim:

1. Apparatus for indicating variations in torque applied to a rotatedmember, comprising:

a hub having means for connecting to a rotated member;

an outer sleeve surrounding said hub;

force-transmitting means interconnecting said sleeve with said hub fortransmitting rotational movement of said sleeve to said hub;

said force-transmitting means having means therewith for moving saidsleeve longitudinally relative to said hub in amounts proportionate totorque forces applied to the rotated member from said sleeve;

indicator means for indicating a reading corresponding to the torqueloads applied to the rotated member; said indicator means including:

a housing connected to said sleeve for movement therewith and having aflexible diaphragm therein;

a piston carried by said diaphragm for constant engagement with one endof the rotated member;

a valve operable by movements of said housing relative to said'diaphragmfor admitting and discharging air with respect to said housing inaccordance with the movements of saidhousing so as to adjust the airpressure in said housing in accordance with the longitudinal movementsof said sleeve and thereby in accordance with the torque applied to therotated member.

2. The structure set forth in claim 1, wherein said means with saidforce-transmitting means for moving said sleeve longitudinally includes:

means for causing said sleeve to move at an angle as it moveslongitudinally with respect to the longitudinal axis of said hub, theextent of such movement depending upon the torque forces developed.

3. The structure set forth in claim 2, wherein said last-mentioned meansincludes:

co-acting inclined splines on said hub and said sleeve.

4. The structure set forth in claim 2, wherein said last-mentioned meansincludes:

co-acting inclined splines on said hub and said sleeve; and

an anti-friction thrust bearing disposed between adjacent ones of saidsplines to facilitate said longitudinal angular movements of said sleeverelative to said hub.

5. The structure set forth in claim 2, wherein said last-mentioned meansincludes:

co-acting splines on said sleeve and said hub; and

a bearing disposed between adjacent ones of said splines and having aninclined race and bearing elements therein.

6. The structure set forth in claim 2, wherein said last-mentioned meansincludes:

co-acting splines on said sleeve and said hub; and

a pivoted link interconnecting adjacent ones of said splines.

7. The structure set forth in claim 1, including:

a swivel inlet connected to said housing; and

an air pressure supply line connected to said swivel inlet, whereby saidhousing rotates with said sleeve while said swivel and supply lineremain stationary.

8. Apparatus for indicating variations in torque applied to a drill pipeby a rotary table having a rotary table drive shaft extending therefrom,comprising:

a hub having a hollow bore for receiving the rotary table drive shaft;

an annular sprocket sleeve surrounding said hub and having sprocketteeth on its external surface for engagement by a drawworks chain forrotating said sleeve;

force-transmitting means interconnecting said sleeve with said hub fortransmitting rotational movement of said sleeve to said hub;

said force-transmitting means having means therewith for effectingmovements of said sleeve relative to said hub in amounts proportionateto torque forces applied through said sleeve to said hub and then to adrill pipe in a rotary table;

indicator means for indicating a reading corresponding to the torqueloads applied to the drill pipe by the rotary table;

said indicator means including: a housing connected to said sleeve formovement therewith and having a flexible diaphragm therein;

a piston carried by said diaphragm for constant engagement with one endof the drive shaft;

a valve operable by movements of said housing relative to said diaphragmfor admitting and discharging air with respect to said housing inaccordance with the movements of said housing so as to adjust the airpressure in said housing in accordance with the longitudinal movementsof said sleeve and thereby in accordance with the torque applied to thedrive shaft.

9. The structure set forth in claim 8, including: a rotary table havinga rotary drive shaft therewith; and means connecting said rotary driveshaft to said hub.

1. Apparatus for indicating variations in torque applied to a rotatedmember, comprising: a hub having means for connecting to a rotatedmember; an outer sleeve surrounding said hub; force-transmitting meansinterconnecting said sleeve with said hub for transmitting rotationalmovement of said sleeve to said hub; said force-transmitting meanshaving means therewith for moving said sleeve longitudinally relative tosaid hub in amounts proportionate to torque forces applied to therotated member from said sleeve; indicator means for indicating areading corresponding to the torque loads applied to the rotated member;said indicator means including: a housing connected to said sleeve formovement therewith and having a flexible diaphragm therein; a pistoncarried by said diaphragm for constant engagement with one end of therotated member; a valve operable by movements of said housing relativeto said diaphragm for admitting and discharging air with respect to saidhousing in accordance with the movements of said housing so as to adjustthe air pressure in said housing in accordance with the longitudinalmovements of said sleeve and thereby in accordance with the torqueapplied to the rotated member.
 2. The structure set forth in claim 1,wherein said means with said force-transmitting means for moving saidsleeve longitudinally includes: means for causing said sleeve to move atan angle as it moves longitudinally with respect to the longitudinalaxis of said hub, the extent of such movement depending upon the torqueforces developed.
 3. The structure set forth in claim 2, wherein saidlast-mentioned means includes: co-acting inclined splines on said hubanD said sleeve.
 4. The structure set forth in claim 2, wherein saidlast-mentioned means includes: co-acting inclined splines on said huband said sleeve; and an anti-friction thrust bearing disposed betweenadjacent ones of said splines to facilitate said longitudinal angularmovements of said sleeve relative to said hub.
 5. The structure setforth in claim 2, wherein said last-mentioned means includes: co-actingsplines on said sleeve and said hub; and a bearing disposed betweenadjacent ones of said splines and having an inclined race and bearingelements therein.
 6. The structure set forth in claim 2, wherein saidlast-mentioned means includes: co-acting splines on said sleeve and saidhub; and a pivoted link interconnecting adjacent ones of said splines.7. The structure set forth in claim 1, including: a swivel inletconnected to said housing; and an air pressure supply line connected tosaid swivel inlet, whereby said housing rotates with said sleeve whilesaid swivel and supply line remain stationary.
 8. Apparatus forindicating variations in torque applied to a drill pipe by a rotarytable having a rotary table drive shaft extending therefrom, comprising:a hub having a hollow bore for receiving the rotary table drive shaft;an annular sprocket sleeve surrounding said hub and having sprocketteeth on its external surface for engagement by a drawworks chain forrotating said sleeve; force-transmitting means interconnecting saidsleeve with said hub for transmitting rotational movement of said sleeveto said hub; said force-transmitting means having means therewith foreffecting movements of said sleeve relative to said hub in amountsproportionate to torque forces applied through said sleeve to said huband then to a drill pipe in a rotary table; indicator means forindicating a reading corresponding to the torque loads applied to thedrill pipe by the rotary table; said indicator means including: ahousing connected to said sleeve for movement therewith and having aflexible diaphragm therein; a piston carried by said diaphragm forconstant engagement with one end of the drive shaft; a valve operable bymovements of said housing relative to said diaphragm for admitting anddischarging air with respect to said housing in accordance with themovements of said housing so as to adjust the air pressure in saidhousing in accordance with the longitudinal movements of said sleeve andthereby in accordance with the torque applied to the drive shaft.
 9. Thestructure set forth in claim 8, including: a rotary table having arotary drive shaft therewith; and means connecting said rotary driveshaft to said hub.